Recently, smartphone owners became the majority of mobile subscribers. And a poll from the Pew Internet & American Life Project says that 74% of them use their phones to access location-based information — directions, local restaurant reviews, movie times and more.

That in itself isn’t alarming. I mean, what’s the point of having a smartphone if you aren’t going to use it to its full potential? Google Maps is probably the most used app on my phone, saving me almost weekly from being late to something.

Giving up your location via GPS isn’t a huge privacy risk — the 18% of smartphone owners who use geo-social services to “check in” to locations are more likely to get burned than someone who looks up restaurants on Yelp. Still, while your average person won’t have access to your GPS data, others might: namely, your local police force.

Last month, the ACLU queried 383 different police departments about cellphone tracking. Of those, 200 responded; out of those 200, only 10 said that they never tracked cellphones.

That’s not to say that police departments don’t have a right to access cellphone data if an investigation requires it. The problem is that there doesn’t seem to be a standard procedure when it comes to police departments asking service providers for your information.

Or, as the ACLU puts it, “The government’s location tracking policies should be clear, uniform, and protective of privacy, but instead are in a state of chaos, with agencies in different towns following different rules — or in some cases, having no rules at all.”

While many police departments do seek probable cause warrants to access cellphone information, there is a sizable number who don’t. Sometimes two police departments located right next to each other have different standards; according to the report, the Kentucky State Police don’t always ask for a warrant even though the local police force in Lexington, KY does.

Standard cellphone records are one thing; GPS data is another. Never in history have authorities been able to track people’s locations with this much accuracy. In Lincoln, NE, the police department asks for “subscriber information, GPS, precision location, and/or lat/long coordinates” for listed phone numbers.

Not every police department asks for GPS information, but that’s likely because it’s a relatively new phenomenon — the wealth of data associated with every person having their own personal GPS system will prove an increasingly attractive target for investigators as the smartphone market grows.

As more people ditch their old feature phones for smartphones, you can expect the controversy to move to the GPS systems in our phones. As of March of this year, there were 234 million mobile subscribers in the United States. That means nearly 90 million people have used their smartphones to find location-based information. This data shouldn’t necessarily be off limits, but people deserve to know that there is a clear procedure in place for when the police can and can’t look through their records.